SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c26f3e6184d27440c56bc01f2ba051605432bf543ccfe8e622c51966420083' 
  AND token = 'bxYZ210EUy9N75nDBZxQRLzu+vtRD/gm/7YILCPF5l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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