SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72fa4f5a0091d5ae5b3682a368b3b7c93db0f585608df0119efb4ed147755cf1' 
  AND token = 'h1bzTLOTvIyLwau/Vi4/8mUwV4zbfPYiMRCdDvDGlU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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