SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12771aa265994a123caefde8f86c17c047f4e620dd64d2b584b3d13f51c21b49' 
  AND token = 'ilIt8pICp7rAx9vqBV0s5Mz8RqgLDVusTDZZSZcu/XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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