SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72fb45808adf394bc322a6478ddf8ccbe8ffed6a5a2cb4e77f7ec53a26ae109d' 
  AND token = 'r9vz1wonB8Njvlbwb5SXw5sv/1K1/yMg/hxljP1qHuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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