SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9755453afee6dcbadcf195b8c56296b79e2e09953b197b602de1d51bd9139eae' 
  AND token = 'kzsimzRRXcTapCUDwEM7jbEOk4CxWKXv+v2qCSvjZWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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