SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a94b46131fe5c610b295220b4181c0ccb85aa3b5f31df946a44adce37511dc8c' 
  AND token = '8eqgQASgJtmXmLggh4KZOGao33NRm/HI/fevzjNB04k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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