SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e1aa1208b0b66f3a39cc74d6d204ee98115ed854bd6156856a92c5ae1a53cb' 
  AND token = 'z615lupnkICsxMC0veYhDcfp5MN3y1054QhQai4O1qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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