SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '475564159818b9438205358a209bbbf8199ab296d494178fb063acce1f307bc8' 
  AND token = 'nyRWT5zCGhGz40FvIZAGMoDYHKpQBhENsmx0PobW2aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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