SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9e32458fb39560c91be57f525347458a88258c8a7e1b6aae1736abe3d4018f5' 
  AND token = 'FjyQKDtSdM4HbSD31K/YL39+tHOqAJcYer2OOPpKEGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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