SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '745cd78284f49f4642cdf329e4afafa09cfe745fece374c2869cdfeb8728694e' 
  AND token = 'G6xXyYOccOIMYO6DvW5SorruX8B3zTOSEf9BxDb0jfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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