SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11748ee696c53ce54654ef0f15742740d1d707fa1f2d6d679cef17852cdbe2aa' 
  AND token = 'gUvXSDy+2UmQScOuLLYVvjyc48C9ZYYtnotrygZ6CDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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