SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb63b48e1af4ab311b2ba6b7dc9cce037bfb56480fa32023d007aa53f4199182' 
  AND token = 'kKCbKlPnKIzuvyLJ9mRu/9LaU0JYZsPWKvtW9JioGrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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