SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de323b1d4f5dd28b64380da2c5725cfd543c984aa555b9275f78c3a3932258ef' 
  AND token = 'msayboNRIqETCQppAIuJhrru3xS6wl5abS5uiK1ATfI=' 
  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"
    }
  }
}