SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2953743bccd923bb1698f61f9873a6870011d2c4aeda082fe422ec08acf89fe' 
  AND token = '7HCt3gq+IIFb9CZ9kJyh+kwtyHvnbYIXTJ+QrwV9UmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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