SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c36b3cf123801882c522e9226c73e4dd9f674b7c279a4ba1168873068a55159' 
  AND token = 'rvpmBqcLLmIfquNKo+tKhjGNWGsUkrFkolIerX54rmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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