SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7281b5ca3b2e90a4e6cfcd625b182e5a76da1dc083bad0fa1b8d4cefaedc53c2' 
  AND token = '4dPXekBU0nc4XhZ7LyrceLZpW0/95fY6mjOcYNpyEgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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