SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27a63b97b0418ebdb89aaa4f801f33cea9947d46765713713909ae6bfb4f2cd1' 
  AND token = 'mJiJBF4+j6NOGx8hJgZLJsMd/hRH66a8gvk6ldbzgyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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