SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d945a2ea3c3dbf080336af0d753e26d64827c263f38ad3df329f3c095c04e0a' 
  AND token = 'BdRpnFstHo9NLdMdX2Q5lRsC4aZ/laSxInv4d9r5lrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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