SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86fd45b228c082c0f2d89a5b4ece0a7277f147945b828cc9cbd1c098eacb4b94' 
  AND token = 'sGWxPqTNY5o10UKzVOeoZvT/9+jAn93xSTObVx9HbKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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