SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5323561284e6f8f7055615bdde208b9937ae8d835773efc2e2d347c2d1f4822f' 
  AND token = 'y90Q9Pl4d++DfbLvLgq/yEXJU+mZue4R3w+5zi7fWVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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