SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0f7f5765b11ef9f95cd811e448fba772353c27f8a60bae2f2933b56da4d1020' 
  AND token = '8TEWbY+zFnrUXqPUvXolF+npWRQ5hbyvEjhH8zJZVIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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