SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da7e55ce49276f4b315857782534df98c0ae61f392121adf99d458303c74202d' 
  AND token = 'GvvajVjeil8A01PVJXGtEMvHZcTzNty+xfK1T+gTugc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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