SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb3e69b282903c368e86d079587298f860eecddfd3985a1b5dd4ad32bcabb59f' 
  AND token = 'GAhFfjilQZsPQyO6LHmr39Lld35mT0aSFNVoF+dKDG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}