SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4465771a75916f1b89431e79a57189d1561f46121b00846ec4b4fd25907ceb2b' 
  AND token = 'DVw28KXgRuU9I3jFNs46itKMWDURR9PPoIOL9WzGAP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}