SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e9192d1791b0c9182828c9383e6c70f8be3120798ed8f6df83726e491686181' 
  AND token = '4Z+v8BBmZNCZzLse7SRhFTPzZ907Y8AWZcQtUKUnxfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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