SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4743c9edb5067b1859ca1f73029a0dc5e956be6a16314d4436177bd56de91215' 
  AND token = 'QEYe2BraH6OnGB9gINp2y5U9idmnHFBeKx7GkO32U/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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