SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fc933b4e203fdc641143a429bb7310598d6b2417e63a600ca9d61fcc266c26b6' 
  AND token = 'QXPxnuDw7nhPMxjv6uyC7UdVHZQ3VwLePpLCGz+DJM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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