SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58d82082c735df9c237c69d080b704b4c8b46bf31513eaaf874bdf1bfeb47d2' 
  AND token = 'kC9spQVuCZPSVKKwa+at4rV2shE51OBslCr0CfUCvWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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