SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70366835dfbb1901b77d97b1913fda8433150adfc75ebbeeaa7a2f22819256cb' 
  AND token = '5SnRXiUZ6mWF/Qxvq+TYiTrFffgmLerBhpGRmcxkd9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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