SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '037e18bb9c041cd65c2a0118dc1facda5cd7550f31a0861f8bc616d6a43592f3' 
  AND token = 'eb+5oNesa9RXKDjkC31jG1pKDmpnh/OrUQQCfhJZ4mY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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