SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce4deb2d1c213d167306971ce528ac5df73cf48baae19ce17f43d99cc7ff113e' 
  AND token = 'dcTWlBXm7OCxh5zfaIMWGzMj0IfbLFt4h6FBhHQinX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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