SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a4264eedaa25df407082e1ba5584960a3025e70ba1b150ad2df86a0214d50a3' 
  AND token = 'UPcatIN2E2SVsv337GsUz+y0mTXVI1wWdXKXaiSTqWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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