SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65260a4897a780d0865dcbcf8f0a85bcc90669cd771fea3e668141dff0da768a' 
  AND token = 'MiRPdhGZDzaheYmX5ZhsmEdTbJP4qtbCxdS2t2b3V5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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