SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3af53f8b0b56057ac9bca4c9fef2ad637101c93204b90d91c6dd77ea97501de' 
  AND token = 'ea5EIX5amtDQej7ve+QH+csiCwE2XHf8+c7mRAh1rOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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