SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d9048f24752f10056184be5f933c56da48df67db2141bda57ce5cc774e97b6a' 
  AND token = 'oJsXs1NKFKwyWlj8kWuNxlCEo55LXQ6tr23z6sTCpm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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