SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '814832e43a4313a65be0cbb1e7f4b9b5b2275367ef11650f091c9241650f8947' 
  AND token = 'Iz9ahVNy+MYNNYgbGCxGxGXKMFFPPswdWSH8MXPN8Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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