Problemas de desempenho com verificação de intervalo de tempo

Estou executando a seguinte consulta do Postgres, na qual associo o uso de um consumidor ao custo do serviço para esse intervalo com base em quando ele usou o serviço da tabela de serviços. A consulta abaixo é uma versão truncada, algumas vezes tenho que fazer até 12 ou mais junções. O problema é que leva 2,5 minutos para executar uma consulta. Como posso reduzir esse tempo? Estou adotando a abordagem correta?

select 
  c.consumption, 
  c.interval_start, 
  c.interval_end, 
  s1.value_exc_vat as service1_price, 
  s2.value_exc_vat as service2_price 
from 
  consumer as c 
  left join service1 as s1 on c.interval_start >= timestamp '2023-03-18T00:00:00Z' 
  and c.interval_start < timestamp '2024-02-15T00:00:00Z' 
  and (
    s1.payment_method is null 
    or s1.payment_method = 'DIRECT_DEBIT'
  ) 
  and c.interval_start >= s1.valid_from 
  and (
    c.interval_start < s1.valid_to 
    or s1.valid_to is null
  ) 
  left join service2 as s2 on c.interval_start >= timestamp '2024-02-15T00:00:00Z' 
  and c.interval_start < timestamp '2025-02-15T00:00:00Z' 
  and (
    s2.payment_method is null 
    or s2.payment_method = 'DIRECT_DEBIT'
  ) 
  and c.interval_start >= s2.valid_from 
  and (
    c.interval_start < s2.valid_to 
    or s2.valid_to is null
  ) 
order by 
  c.interval_start desc

Isolei o problema nesta seção da consulta em cada junção:

and c.interval_start >= s1.valid_from 
  and (
    c.interval_start < s1.valid_to 
    or s1.valid_to is null
  ) 

Parece que encontrar o intervalo certo para entrar na mesa leva muito tempo. Os períodos de tempo podem variar de 30 minutos de intervalo até alguns meses ou anos para as tabelas de consumo e de serviço, por isso não posso fazer uma simplesc.interval_start = s1.valid_from and c.interval_end = s1.valid_to

Aqui está um EXPLAIN (ANALYZE, BUFFERS):

"QUERY PLAN"
"Sort  (cost=5523752586.99..5549030615.96 rows=10111211585 width=28) (actual time=140588.278..140589.028 rows=20593 loops=1)"
"  Sort Key: c.interval_start DESC"
"  Sort Method: quicksort  Memory: 2216kB"
"  Buffers: shared hit=396"
"  ->  Nested Loop Left Join  (cost=0.00..2633916836.23 rows=10111211585 width=28) (actual time=12.169..140546.307 rows=20593 loops=1)"
"        Join Filter: ((c.interval_start >= '2023-03-18 00:00:00'::timestamp without time zone) AND (c.interval_start < '2024-02-15 00:00:00'::timestamp without time zone) AND (c.interval_start >= s1.valid_from) AND ((c.interval_start < s1.valid_to) OR (s1.valid_to IS NULL)))"
"        Rows Removed by Join Filter: 559372220"
"        Buffers: shared hit=396"
"        ->  Nested Loop Left Join  (cost=0.00..3979716.14 rows=4302977 width=24) (actual time=0.058..27617.147 rows=20593 loops=1)"
"              Join Filter: ((c.interval_start >= '2024-02-15 00:00:00'::timestamp without time zone) AND (c.interval_start < '2025-02-15 00:00:00'::timestamp without time zone) AND (c.interval_start >= s2.valid_from) AND ((c.interval_start < s2.valid_to) OR (s2.valid_to IS NULL)))"
"              Rows Removed by Join Filter: 176848172"
"              Buffers: shared hit=196"
"              ->  Seq Scan on consumer c  (cost=0.00..337.93 rows=20593 width=20) (actual time=0.007..21.813 rows=20593 loops=1)"
"                    Buffers: shared hit=132"
"              ->  Materialize  (cost=0.00..214.29 rows=8588 width=20) (actual time=0.000..0.272 rows=8588 loops=20593)"
"                    Buffers: shared hit=64"
"                    ->  Seq Scan on service2 s2  (cost=0.00..171.35 rows=8588 width=20) (actual time=0.006..0.891 rows=8588 loops=1)"
"                          Filter: ((payment_method IS NULL) OR (payment_method = 'DIRECT_DEBIT'::bpchar))"
"                          Buffers: shared hit=64"
"        ->  Materialize  (cost=0.00..675.37 rows=27164 width=20) (actual time=0.000..0.896 rows=27164 loops=20593)"
"              Buffers: shared hit=200"
"              ->  Seq Scan on service1 s1  (cost=0.00..539.55 rows=27164 width=20) (actual time=0.002..2.830 rows=27164 loops=1)"
"                    Filter: ((payment_method IS NULL) OR (payment_method = 'DIRECT_DEBIT'::bpchar))"
"                    Buffers: shared hit=200"
"Planning Time: 0.107 ms"
"Execution Time: 140590.312 ms"