SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53123dd023934b0babb4995db219a8b84baab125426f118b623a6f9494038c19' 
  AND token = 'OXBhpfb4wcvJmnBksSV01CcA1jsinvF6QVJB6SsIQ0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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