SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd88627fccefca9a8688436da61d650bb22eb1035ea16e53620c9b3f6685d7e9e' 
  AND token = 'IsBYBqzQszPhVBTZgWoWsxMxJby+V/b8FgcLNgG6dZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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