SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f53d24bb8ad44cc9c5dc1e540577a05d9fa81fc1d8ba25d651a7c3731bf24a1' 
  AND token = '+0RZm7++2tBUhzpQGDFsysZeMLOewemDERuIEO1J4sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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