Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b273b09ed137060197b1dd6c80e8dbd1e1ebe9dfbcf304764b6d3e873e0d2d4d' 
  AND token = 'm9VbK1+aUYvNfgSuOuU1EDJ020ElAyDJnkg8ZRrl0Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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