SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '51f983769e7292bf47d3d5e9312f3efec467b8e98d8ed5a71198230bc8979bbe' 
  AND token = 'pzKHMfGa323N0TNdqY3nHa29qJay9AwJ7+6r/h7R/tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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