SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f9b6ccd7965590545b595da0f1924889afda436ff2ce483a1e240cab0d61187' 
  AND token = 'WFzpUyf9UcCOnXRUasytMUf+OOSqhRojKDKvxcBAUD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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