SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c19a94578179ac6a8a2283bf79700f8613477cf85c77cdb12bffd340d24afb9f' 
  AND token = '22kKhzhY7/wSv7uzeJiUi2r59o+LFySojBColJkY7lY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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