SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0221ad85a9c15cbb0c9ebf7d05fd9e41bec45f1ebc0de5f8a786cebf506be5ba' 
  AND token = 'hcSSbggsr5vjz5dLjAwMqwhcHxPXPvQcPOOLPuEcs/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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