SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80ea68920d5ca6311039abcf6fe3b4e13b612fa9f247076ed8096edff605edd7' 
  AND token = 'f36F4QDS8TgqU1yJAHFZn9jSN8QPMVapLY8d8Dv+Hq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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