SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a41afeaa842a11c5d23412173c84f0984a5462050448818223dcb28bd8c89437' 
  AND token = '2sXj9tao4ikAgC+JLJpOvjUPfvo4RKJYx7INoT+aojU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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