SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6990088e807123602e4bfe8b33319044dcedc6a34fe10691161284cf7e6ef175' 
  AND token = 'NRcHVShGiXxYqOaihyOP0W0AFNJfEDEkFzYb93RTgaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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