SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '924df52e0d3d38a3a1f893b04af863afd1bd4bedb30f4823ee1e34a2341e8e93' 
  AND token = '3g6BxiuT/mMlBihvd/lMP+90FuWibdMzv3gde4jKOdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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