SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f1d01179a8b1592ec657673995e376782a27d141a60ece40e26b9ef1952ef4a' 
  AND token = 'cv9iXeBo5h06JZOT9GD7epllSqYMYSfDTadwK0SdwrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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