SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e38648d38a8c1d1fcb639707e36d64ac0beeee3d0be40de0d9feca2283eabc3' 
  AND token = 'WFvPuEljx1qUcXct09ba+zuG+xDxqs84SNJfZmuaqbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables