SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9218426827112dcf68f493bd38553822f9ab34290921104df6bb6c9cb2ff1790' 
  AND token = 'N9sCEkYzwyhJd/HIISG0IZ98BLkP8K/xfUvGQkJLA68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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