SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53e13a0db0aba2975ddf9c55c4a57ffb46c16e84ce2de701f2fd2bc5519b5059' 
  AND token = '3VnWdCp5lV0HQUyNkmwzeQe9MmwHJOYnBtEblSwg+jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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