SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28b4079719f602c819d27ef30ee93a9be3b5059b134a368ecd32526c3105ba04' 
  AND token = 'nECB4co8JJEWcKPS+St8ZNa/jq6qLqHPC6di3/A2Og4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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