SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ef60eb7c50c9ccf49f15da8d188b84de34e28046c8170fac4c2ab5daedccb8' 
  AND token = 'wtHj7RMf+NUoT9HGbO86LTELSqtvZFL3DbXhGzmhPSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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