SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41943c373a4c7c0ab4dcbb6be0eed1293c065dab18a16e2207ee85c8a22c5dc5' 
  AND token = 'LSNlsxHK4awHuELFbUoyTGJoNnvhnZGfptdNmMbZ8ko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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