SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '399e8ea2b57dc1fd6f68ee40e5123ddbdbbe2e12b215bbe52e85600cdcdd8e33' 
  AND token = 'ijm92WNjrVr0KK772hekmh0004l4PDtfrg79UQb6W4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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