SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8cf7b0a5b4ce1ae58676ad5de22c7b2408707c5dd8e49bc70c51441814beb79' 
  AND token = 'yf03sxPzWoMkf4Iw4g0pyt18yH6BCzaa0TzuOkk/DMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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