SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd99d41dd9e43514f1b260c86581874cff6c4c5b0e65583dec1e37ae9bf43f648' 
  AND token = '1utZgaTmjgmSopZHsEKE0U7ksmGzTnhMVeVQ7/qXQWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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