SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a54467de4082799e202d40570f3a8c9a390474b7076677b5f91444b7d4ffec1' 
  AND token = 'b3g+luP4jhJCMCOlIGdBIBg+sDCiRgbAYgzYW7p2QtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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