SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac234bd65ab71180aeb9b7d55ab03b79eef107e809fac1fdaa87bd32af06a8c' 
  AND token = 'uEmJ78iA5G+taWLOpDoa9NiFOrgXVw3TJdRAU0JKkKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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