SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e663150cb8163db96be9a5240d892e977bfe348c6395b672a3e9d5578171ef18' 
  AND token = 'dsXqAMJ8A1fMtcdYWUFfcC6rlwTN+L65p0rhg11KKK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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