SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c91970409c7ae7944500e1c5fd987e0994e4b190b9af1a901fbaac13a22ff04' 
  AND token = 'NA9g9f9wbxWjyTIKtvyHbmUvGWiJWKOEyjkPpuKACio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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