SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb9c4129fb202edc35759fb9dc251163a7c04650d5dddcbf289c6e43d4e747e2' 
  AND token = 'PyEed2Hol1o1ClnO+7XjpH5SWTkAxlsSHMWq9mwSNQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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