SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4da6b5bf766d8f52e903440745aff6a1ca80550d2226c49c75f0d91ce3c618aa' 
  AND token = 'RA8+J1FsRtDH1UpBL4PLtHajg5rb3anwsQcbST6WcP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}