SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7359fcf6973a7a84570a65962fb3ad7b04d6645536082d92b4d02e03c2fe402e' 
  AND token = 'utV7n309jLqXVj/opHxPM/hRxYSX5Zlvy0xcIAt4l2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}