SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '451d0ac1113d203576edd04e0812691a1a48cc817953a890efaf9f5bfbd7df06' 
  AND token = 'YZhTRxKcBdiWcBxUJnazcj8gp6vGTMenz+PKtaMhz70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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