SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc6bfb03973d4dc49f4338efffca7264990ae823d20bcf694d131160230e72c9' 
  AND token = 'ASFpVWjolMLf8myOK5ohTBorVG5B3xllO42QBfJCkHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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