Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6e6c4b821cad6d7547712bf24d7f21058e1278759da9052aa77b16798628c52' 
  AND token = 'eUh+VVRAs71BepZq9wZ8Ef0sSsu58lQaUkL18Rq01fo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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