SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0837209afc3fbae7097cff1441f57dd848049e6bafc1e2d3159e76aed2817645' 
  AND token = 'uyxAJJzK5l3bxluyLJPRFpm+cWtKBXMneQESQppKpgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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