SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f073b5fca03546a5314622813e09b2ab8acfd1dea642d210bac4c319569b847' 
  AND token = 'g0KF2hEFo4qa27eVfJ/v4UHGhuCL+i8Uh5rCV6lMs5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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