SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b19f663fc6a7eafa77b28848cc80317d0eaa402b541f98af59ac4aa13afa157' 
  AND token = 'D0TftbgDpJ2IaB2tllEGdqTMTsKy6DP9A2HldkeCHdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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