SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b8993541bc9ff000af4e6dcfcd5b55579494296809bce9fbd3d27ecc2967e66' 
  AND token = 'VE+xGMwoB4wYODNSXnAPLuHqiLjEbN+iTu4PwoPIeMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}