SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '367a1b90ee028cae142d02967948e2aae0b1152cc364eb5ea4f76be6f3b90bf8' 
  AND token = 'EX8sTs49TFNjlNsZpzSu+MKRXLLsRdLifLcv3LuUO9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}