SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16afa8e657a2b6092789c21088b040bc812a3c5312ddd991fc9908df898c11b5' 
  AND token = 'SZKYmG5MRMw4UvZ9NQiVhG14lrgwvG3lKF0vAaJDWuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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