SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ef24bdaf432346f87b391bb8acbcf9e31da8e1a2f8bb2124ebe992da361734c' 
  AND token = '4qQHVmLB+s6mP5HYG0/8hZiwbkFBxiBKEi9Oq4UINAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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