SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c37bdd2c6dd9988805f0ed476887a901f569e7843923220a1cb96c8f0aaabbf9' 
  AND token = 'wuMsAX7FiEw0s5mWoPCzjXrwfNBfjhG3tXq2hnZ+lgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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