SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d91b8437dacb8d94bb3748941eb74b28e8b778b8ba66b443c281e6b122404be' 
  AND token = 'ydpWTT59SY7R5hSVOloAUmEJ+4wEveiU/v5GIWhfA0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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