SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '010729c5cbdd956c55ff7d3eea36850393668bf649628bb6da33f35391e20b77' 
  AND token = '4TVxuw1BvojLQuLq94zX0GeYcoBPVdj8PGQseU6+1jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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