SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1048a55bf7121f1fccadcf50448fddc3ccaf38ac8e6c61508be4bc40d71f2a24' 
  AND token = '1R16vHmRaLtnHNB2C/b8eao4Ke57zTiCjMZIUAbn94w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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