SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5123572150ab65f0b79a7f8737ea09ed118b6c986491b30dc31233717aab1a24' 
  AND token = 'bQl4y2wjgTcLkd/kPEXO86VjM+3Jb2ulnUiDVxItygI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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