SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd967b30d796d259f161680602dcb2bd28666ae4514cc753bbfae9f94763704dd' 
  AND token = 'Ll6GuDLuVNmF5KtODafyz8Wb7NT8Z31iaqs3VUSMznc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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