SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db3420959024b50d5135260ad38fa7d09ed9f6fb4888c4db79dbc38bfa5039a6' 
  AND token = 'e3Bhv19IsNOWNJIuKacAkLl95cad78cPEGjIbCkhwL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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