SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0854c97e23f059eb61e3be09c4d4f2ad2da23b683cadc180674b8d0c9b8fc6d5' 
  AND token = 'sOnHRJ7rVttZOyNSLGaY5LDdtuZvsojU1pGKz6S3/S4=' 
  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