SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d165918c36217acd4136f86284b03126c0f395ccc90eec7f745f3d26aa6b451' 
  AND token = 'toUE1WwIHs6kuTqZeHmO58Bs5FSUgMQ5tfkr9/wrZfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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