SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cc6b9fe01db39d91f4d681954aeee8007aba45c6c2589be1d44f97169a22784' 
  AND token = 'KLyJHF1Ig69Qfd1cn3qTLGE4hWBL7+T8MwGTzF5jH/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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