SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f87b35c2c4787ee579dc3085fd7828d4bf23399e72795b2d24f85f661cd6790' 
  AND token = 'ucpWU/+K13TaVQSB7qcRvKNoREjjl2JVNuNcSX0FkfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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