SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bfec7fdef62d968d1fc16fe6d1f8dc3300a96d73520611a9fb6d24819b378299' 
  AND token = 'C5svyK/l9aGHnJacIMjm/7uGXVrkksU4nZzkgkvEqmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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