SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '846c300ae6fc10074bee5c558797fa2f7fb493b58b454bf202703d88a86d9cd6' 
  AND token = 'ti0F/mJmdzaaWdi2l+hWNH5ZTabABvI+doBGQv1UF/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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