SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20e6fe3b928c5f5b2a14246fb1c20c1863302698b78e60334c201a76a3644b6b' 
  AND token = '6pxq5Wo2qIYUn+9o9Hxlh7enQXj4XQiySc9h0Z5wqno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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