SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '272d1994b9c704e36b3d76668a874ddf7f1456584247ff59db3de8ab0c3ea5f7' 
  AND token = '6Bx1C4ZoJGbEv+DJh+lshGv48GGIP3jTAqFnJxmwlJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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