SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2fead23ab73a0901734865f72f543948d13dc86d78599a6100b86305b4e2333c' 
  AND token = 'R2wl2Hj4RiKrMOZZ9yKe2jS74HhR2MnhpQ0jCi7LJFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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