SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17da7b52bccc3b165c83e418aee73a5ae212142ac3e8dfc13ada70f31e216be1' 
  AND token = 'DRShG8lEU4YpOVN+3FQJtUgaDK/+30kvHf5vI4EK6fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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