SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66c08413e74bc6d8ea1b4f0368791d465ce8fb679de6341dba49989b49d1892d' 
  AND token = 'fGVejgQDMHMQ0N8NQdxZHP0lNGILeXdNaeYxpTCwZZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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