SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '04e274dda7f780b3b63c17b6b64eb3909420d376a80bc1b5c986b050c055a840' 
  AND token = 'eu5vhEdNXveioYxx2J3LCHHczjsIwABKIzikswnvpw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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