SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35e6be0acebd1647a4b1d1e98b5b33559b8520efe331d221433bba0daa36e4ab' 
  AND token = 'f6FhA/Spfv6C5z97cwJl6aOfJWMB4AiHk1t0XxsurRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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