SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebfb2bf0d3de60b5de53179bb4033f4fd6d991e6327134c7fbb6aa9776693faa' 
  AND token = 'nKg4uavnymmlIItK6dTWedRv9hFqqm0uR4+tsFthRtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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