SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c423e9dd9a83354a325bbaeb679d65d55c036f6a8c160d50a83b69ed38c3cb5' 
  AND token = 'QTTzWHtQvpkNivFwzGT5U8wA7YlqrWbtoVa1AVihyRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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