SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0334d952daafc7fa38aebfec5b2d7176da7f5c08985deb2c83928558cf15ee2' 
  AND token = 'QyRmBMyzoXGmOdJN1oLg5EOMQ/oX8Ax+wzWEeUPo25s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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