SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '006e1000924932bb3786ff58634d67b92be9688b4c104335dd2331c1fbf70264' 
  AND token = 'Cus/hvhrCL/3cV60twc45QOcpkuVuoB5EAGy5hlFnyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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