SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bdddc3893039d1e23c8fce779190c796402399821f330caf7231afa2946f2d0' 
  AND token = 'DBLB3zU+frNaYsVtAV6cXQNB0v4TZ6zhd3lVt8MA2NM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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