SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a28afa717f2d2d7e8e2426626e7d931cdee6bcff2ad50d9cf5e050a8a50f00c2' 
  AND token = 'zFMT03qeRW0We7/GxEuiVpaSRG6nr6AQ3uLbFkpzIvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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