SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9670a364c92d5abd52df73f74795c9091ab1c4cbb1cdb74cea5c96a8045d3bb3' 
  AND token = 'kZe9gBhmarhe1W8hhmvg029nDpUtcmmbIA796ijxdh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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